Automatic relief-valve



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O. AHRENS & O. H. FOX.

AUTOMATIC RELIEF VALVE.

No. 559,881, Patented May 12, 1896.

AN Dim Bil-ABM. PHO'I'O-UITHQWASN NIGTOILD C.

UNITED STATES PATENT rrrcn.

CHRISTOPHER AllRENS AND CHARLES II. FOX, OF CINCINNATI, OHIO.

AUTOMATIC RELIEF-VALVE.

SPECIFICATION forming part of Letters Patent No. 559,881, dated May 12,1896. Application filed June 24:, 1895. Serial No. 553,851. (No model.)

To all whom, it may concern:

Be it known that we, CHRISTOPHER AHRENs and CHARLES H. FOX, citizens ofthe United States, residing at Cincinnati, Ohio, have invented new anduseful Improvements in Automatic Relief-Valves, of which the followingis a specification.

Our invention relates to relief-valves to be used in situations where acolumn of water is to be maintained under a limit of pressure as, forexample, in forcing water through hose, &c., liable to be burst throughexcess of pressure.

The object of the invention is to organize and produce a compact,simple, and effective device adapted to be attached, for example, to afire-engine and capable of adjustment to any desired pressure andoperating automatically as a safety-valve to prevent any undue pressurein the hose.

To this end our invention consists in the relief -valve constructionhereinafter more fully described adapted to be applied to thedischarge-main of a pump or pumps or in other situations to relieveundue pressure without loss in the normal dischargecolumn.

lllechanism embodying our invention is illustrated in the accompanyingdrawings, in which- Figure 1 is a vertical axial section of the devicein the line of vision indicated in Fig. 2, and Fig. 2 is an elevation ofthe device.

Referring now to the drawings, A designates a section of tubing adaptedto be inserted in and constitute a part of the discharge-outlet, and B alateral tube or passage formed as part of the same general casing,communicating, when the device is attached to a fire-engine and inoperation, to the atmosphere or suction side of the pump. The tube B isattached laterally to the tube A through an intervening chamber B,opening into both, the communication being through a perforatedpartition b, utilized as a valveseat and controlled by a disk valve aseating upward. The valve a has an enlarged lower guidestem a,projecting through an opening in the casing B below, and an upper stem aterminating in a piston 1?, operating in a vertical cylindricalextension 13 of the casing l).

The piston P, stem a valve a, and stem (1, are arranged in the same axisand are preferably formed substantially as one piece of metal. Thepiston is furnished with the usual packing, and a stuffing-b0); for thestem at is provided by countersinking the lower wall of the casing 13'around the aperture, in which is placed a leather or rubber gasket 0,upon which a metal washer c is superimposed, all being held in theirplaces by a spiral spring S, surrounding the enlarged stem a and bearingabove against the under side of the valve a, the spring having theadditional function of supporting the valve a against the weight of theparts and normally retaining the valve against its seat by its excess ofpressure. The enlarged stem a, besides serving as a guide to the valvein relation to its seat, has the further function of reducing the areaof pressure upon the under side of the valve a.

The communication between the casin g 13, at the under side of the valvea, and the tube Abeing free and open,the pressure in the tube A operatesupon the annular under surface of the valve a around the stem (1. toretain the valve a closed upon its seat, excepting as hereinafterdescribed.

Adjacent to the upper extension B and preferably parallel to it, is atubular enlargement B of the general casing opening below by a somewhatcontracted aperture through a partition 61 into the tube A and above bya lateral passage 6 into the upper end of the cylindrical casing 13above the piston P. Upon the partition d is seated a plug-valve f,having a cylindrical stem f, of corresponding diameter, with itsseat-opening extended centrally through its sleeve g, threaded fromabove axially into the casing 13 and embracing the cylindrical extensionof the valve f with a close sliding fit. The lower end of the sleeve iscountersunk, and contains a leather or rubber gasket f and a metal ringor washer f upheld by a spiral spring 5, embracing the stem f and seatedbelow upon an annular ledge of the stem, thus tending to retain thevalve f normally seated. The tension of the spring 5' is thus made ameasure of force to retain the valve f seated against the upwardpressure in the tube A, and may be increased or diminished at will byrotating the sleeve 9 in its threads, thus compressing orrelieving thespring. The upper end of the sleeve g is for this purpose provided witha handle g and a jam-nut g for conveniently operating the sleeve andretaining it in adjusted positions. A minute aperture 0 is providedthrough the side wall of the casing B which remains constantly open tothe interior space.

The general operation is as follows: The device being attached andconnected as indicated, and the spring S, bearing upon the valve f,adjusted to a given. pressure, so long as the pressure in the tube Aremains below that retaining the valve f seated, no action of the deviceoccurs. \Vhen, however, and so long as the pressure in the tube Aexceeds the spring-pressure upon thevalve f, the latter is raised fromits seat, water flows upward through the casing B and passage 6 into thecasing B and by pressure downward upon piston P (whose area exceeds thefree area at the under side of the valve a) unseats the valve to, andthus opens communication from the tube A into and through the passage Binto the suction-passage of the pump or to the atmosphere. As soon asthepressure in the tube A again diminishes to or below the: given degreethe valve f again seats and the water above the piston P escapes backthrough the passage 6 and out through the orifice 0, thus relieving thepressure upon the piston and enabling the spring S and theliquid-pressure in tube A to seat the valve a, and it is retained seatedby the pressure in the tube A until the described operation. again takesplace.

The superficial area of the piston P is the same as that of the openingof the valve-seat b, and it will be perceived from the describedconstruction that as the valve-seat Z) and the piston-chamber open atopposite sides of the relief-passage B the piston P perfectly balancesthe valve a against any back pressure or vacuum in the chamber B,whereby the action of the device is entirely unaffected by either ofthese conditions in the relief-pas sage outward of the valve.

hen the valve f is lifted and the pressure in the tube A is brought tobear upon the piston P downward, it exceeds the seatingpressure upon thevalve a (omitting the force of the spring S from the consideration) inproportion to the difference in cross-area be tween the stem of and thepiston P, since the extension of the stem at through the casing B servesto relieve from pressure an area at the back of the valve equal to thecross-section of the stem. As the force of the spring S is practicallyonly a counterbalance to the weight of the parts, with a slight excess,it does not materially affect the described action.

The limit of travel of the piston P (and by consequence the extent ofthe opening of the valve a) is regulated by an abutment-screw 7L,threaded through a yoke-standard 1', extended beneath the casing Bacross the projected axis of the stem a. By setting up the screw thedevice may be made entirely inoperative when desired.

These being the principal features of the invention concerned inproducing the desired functional operation, it remains to designate moreparticularly certain features of construction conserving efficiency ofuse under ings B B are supplied with screw-caps, c0n-- stituting theupper and lower walls of the casings, respectively, by whose removal theinterior parts can be inspected and adjusted or removed with facility.Thus by removing the cap at the top of. chamber B the packing of thepiston 19 may be tightened. By removing the cap at thebottom of chamberB the entire valve, stem, and piston can be removed and replaced. Theupper opening of the cas ing B is closed by the sleeve device beforedescribed, by Whose removal the valve f and its stem, spring, andpacking-rings can be lifted out. Either one of the internal moving partscan thus be removedor replaced without disturbing any of the pipe-jointsor interfering with the general operation of the engine beyondtemporarily stopping the flow of water through the tube A.

Not only is this construction simple and compact, but While in actionall parts remain completely drained, excepting the chamber 13, which ispractically an enlargement of the tube A. The advantage in extremelycold weather is that there is no danger of freezing, inasmuch as theheat generated by pressure and friction in the tube A gives sufficientheat to all parts in immediate contact therewith and the remote partsare freely drained of water.

Incidentally the aperture 0 not only serves to drain the upper chambers,but also by the escape of water under pressure gives a visual indicationto assist in adjusting the spring S to any desired gage-pressure.Besides this, it allows leakage past the valve f to flow oif withoutaffecting the piston P. It will also be observed, as a further point ofadvantage, that there is no obstruction whatever in the waterway A, andalso that no grit or sediment can interfere with the action of theparts.

XV'e claim as our invention and desire to secure by Letters Patent ofthe United States 1. In an automatic relief device of the characterindicated, the combination of a transmitting-t ube; a relief-passage avalve-chain ber connecting the transmittin g-tube with therelief-passage; a cylindrical pocket opening from the relief-passage inthe projected axis of the valve-chamber; a relief-valve seated in thewall separating the valve-chamber and the relief-passage; ag0verning-piston operating the cylindrical pocket; a stem connecting thevalve and piston across the relief-passage; and a cylindrical extensionof said valve, approximating the diameter of its seat-opening, operatingthrough the opposite wall of the Valve-chamber, substantially as setforth.

In an automatic relief device of the character indicated, thecombination of the transmitting main, lateral relief-valve chamber;relief-passage; cylindrical extension; and the valve constructed andoperated as described; and a spring surrounding the valve-extension andupholding the valve against its seat independently but in aid of theWater-pressure, substantially as set forth.

